Honing tool body abrasive slot insert



Nov. 5, 1963 R. ENGLE 3,109,266

HONING TOOL BODYABRASIVE SLOT INSERT Filed Feb. 20, 1961 v 2 Sheets-Sheet 1 INVEN 1176267; 6'. Z 1

Nov. 5, 1963 R- C- ENGLE HONING TOOL BODY ABRASIVE SLOT INSERT 2 Sheets-Sheet 2 Filed Feb. 20, 1961 INVENTOR. 2 02672 C. fry/e "gab, nwzzKs:

United States Patent 3,109,266 HONING TOOL BODY ABRASIVE SLOT INSERT Robert C. Engle, Livonia, Mich., assignor to Micromatic Hone Corporation, Detroit, Mich., a corporation of Michigan Filed Feb. 20, 1961, Ser. No. 90,385 7 Claims. (Cl. 51184.3)

This invention relates to honing tools and particularly a honing tool having new and improved means for retaining and supporting the honing stones in the slots thereof.

The present invention has reference to honing tools of the type in which the honing stones or abrasive elements are retained within slots in the honing tool body by frictional engagement. Examples of such abrasive elements may be found in United States Patents Nos. 2,467,094 and 2,675,654. These abrasive elements generally include a bonded abrasive stick encased and supported within an outer shell of plastic material. The enclosing plastic shell is manufactured to rather strict exterior dimensional tolerances, so that it may be fitted within the slot of a honing tool and be retained therein with sufiicient frictional force to prevent it from being thrown out of the tool body by centrifugal force upon the rotation of the tool, yet be subjected to being fed or advanced in a radially outward direction by means of an expansion member disposed within the body of the tool. Substantial difliculties have been encountered with the use of such honing tools and abrasive elements, particularly as a result of the abrasive wear of the slots of the honing tool. Such wear requires frequent replacement of the honing tool body and also permits the honing stones to be thrown out of the body because the slots are no longer of a size adapted to frictionally grip the stones with sufiicient frictional force to retain them in the body.

It is, therefore, an object of the present invention to provide a honing tool having replaceable inserts in the slots thereof adapted to absorb abrasive wear which would otherwise be absorbed by the tool body and having means for frictionally engaging the abrasive elements inserted in the slot to hold the same in the slot irrespective of reasonable amounts of wear of either the slot or the insert element itself.

Other objects of the present invention include the provision of a honing tool having slot insert elements which are extremely inexpensive of cost and which may be readily removed from and installed in the honing tool, which permit the more rapid and convenient installation and removal of the abrasive elements, which improve the uniformity of the abrasive element feed rate and the workpiece size control, which contribute to the speed and efiiciency of the cutting action of the abrasive ele ments and which may be produced with a minimum modification of presently utilized tools.

These and other objects of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a fragmentary elevational view of a honing tool embodying the principles of the present invention;

FIG. 2 is a sectional view of the structure illustrated in FIG. 1, taken along the line 22' thereof;

FIG. 3 is a sectional view of the structure illustrated in FIG. 1, taken along the the line 3-3 thereof;

FIG. 4 is a view of the retainer element shown in FIG. I removed from its associated structure and being shown in its free state;

FIG. 5 is a fragmentary view of the structure shown in FIG. 1, with the abrasive element removed from the slot and the retainer being shown in the position it assumes prior to installation of the abrasive element;

FIG. 6 is a view of structure similarly illustrated in FIG. 3, showing another form of the present invention;

FIG. 7 is a fragmentary view of structure similarly illustrated in FIG. 1, showing still another form of the present invention; and

FIG. 8 is a sectional view of the structure illustrated in FIG. 7, taken along the line 8-8 thereof.

Referring now to the drawings and particularly to FIG. 1, a tubular honing tool body is fragmentarily illustrated at 10 which is adapted to be rotated about and reciprocated along its longitudinal axis by a suitable drive shaft (not shown). The body 10 has circular cylindrical inner and outer wall surfaces 12 and 14, respectively, and a plurality :of slots 16 therethrough which are illustrated as being elongated in a direction axially of the tool and which are open in a radial direction in order to receive and support radially adjustable abrasive elements or honing stones 18. The honing stones 18 are illustrated as including a bonded abrasive stick 20 set within a surrounding shell of plastic 22 so as to be exposed only on the working face 24 thereof.

Disposed within the honing tool body 10 is a honing stone expansion member 26 which is axially slidable relative to the body 10. The expansion member 26 has spaced inclined cam surfaces 28 which are conformably engageable with inclined cam surfaces 30 on the rear of the shells 22 so that, upon downward axial movement of the expansion member 26 relative to the body 10, the stones .18 will be advanced in a radially outward direction. The outer peripheral surface 32 of the expansion member 26 has a generally circular cylindrical contuor which snugly but slidably contacts the inner wall surface 12 of the honing tool body 10.

The honing tool body may be provided with any desired number of slots 16 disposed in both angularly and axially spaced locations. The present invention comprehends the utilization of a honing stone retainer element or spring clip insert 34 fitted within each one of the slots 16 in a manner adapted to frictionally engage the particular honing stone 18 carried within said slot. While it may be possible to omit the retainer 34 from selected ones of the slots 16, or the particular shape of the retainer 34 may be varied between the slots, the details of construction of the retainers 34 are shown in several embodiments with particular reference to one of the slots 16. The retainer 34 illustrated in FIGS. 1-5 is shown as having an enclosing wall portion 36 extending around the stone 18 and lying flatly against the side walls de fining the slot 16. The enclosing wall 36 defines an opening extending radially through the retainer 34 for the reception of a boning stone 18. As particularly indicated in FIG. 5, the slot 16 will be seen to have opposite side walls 38 and 40' on opposite lateral sides of the slot 16 and side walls 42 and 44 at the bottom and top of the slot 16, respectively. As seen in FIGS. 4 and 5, the retainer wall 36 includes a base portion 46 lying flatly along the slot side wall 40, arcuate wall portions 48 and 50' at opposite ends of the wall portion 46 adapted to engage the bottom and top side walls 42 and 44, respectively, an arm portion 52 adapted to lie flatly against the upper part of the side wall 38 and an arm portion 54 adjacent to the lower part of the side wall 3-8.

As may be seen in FIG. 5, the central portion of the arm 54 is spaced slightly away from the slot side wall 38 in the absence of a honing stone inserted therein. This results from the fact that the arm 54 is provided with a bowed or inwardly inclined portion 56 at the end thereof adjacent the portion 48 and an angulanly inclined extension 58 adjacent the free end thereof which terminates in a flat pad or terminus 60. It will be seen that the side wall 38 is provided with a recess 62 having a flat bottom wall parallel to the side wall 38 and spaced away from the side wall 38 in a direction away from the opposite slot side wall 40. The extension 58 extends the depth of the recess 62 when the retainer is inserted in the slot, so that the pad 60 lies flatly against the bottom wall thereof for slight shifting movement therealong upon the insertion of the stone. The retainer 34 is desirably made from spring steel and the arms 52 and 54 are inclined outwardly in their normal unstressed condition, so that they must be deflected inwardly toward the base portion 46 in order to permit the retainer to be inserted in the slot. When they are then released, arm 52 is spring-biased against the upper portion of the slot wall 38 and the pad 60 is biased against the bottom wall of the recess 62.

The retainer base portion 46 is provided with an outturned flange 64, the arm 52 has an outturned flange 66 and the arm 54 has an outturned flange 68. As may be seen in FIG. 3, the flange 64 fits within a flat groove 70 milled in the expansion member 26 adjacent one side of the cam recess 28, while the flanges 66 and 68 are disposed within a groove 72 milled into the outer surface 32 of the expansion member 26 adjacent the opposite side of the cam groove 28. Said grooves are, of course, provided adjacent each of the slots 16. The flanges 64, 66 and 68 contact the inner peripheral wall surface 12 of the honing tool body at their radially outer sides and are thus confined between the base of the grooves and the honing tool body, so that they are held against radial movement during feed movement of the honing stones 18. Thus, upon installation of the retainer 34, the arms 52 and 54 may be compressed inwardly toward the base portion 46 by a sufiicient amount to permit the flanges to be moved inwardly of the wall 12 and thereafter manually released to slide into the grooves 70 and 72.

FIG. 6 illustrates an alternative form of the invention in which a honing tool body 74 is provided with milled slots 76 and 78 on opposite sides of an abrasive element slot 80. Thus, a retainer 82 may be inserted in the slot 80 so as to lie against the side walls thereof and is provided with flanges 84 and 86. Thus, the flanges 84 and 86 are confined between the bottoms of the slots 76 and 78 and the normal circular cylindrical outer periphery 88 of an expansion member 90 and on opposite sides of the cam slot 92 formed in said expansion member. The retainer 82 is thereby held against radially outward feed movement with a stone 94.

FIGS. 7 and 8 illustrate another form of the invention in which a retainer clip 96 is supported within the slot 98 of a honing tool body 100 and is provided with a flexible arm portion 102, similar to the flexible arms described in the previous embodiments, for frictionally engaging a honing stone 103 adapted to be radially fed through the slot 98. In the retainer 96 illustrated in the present invention,

the wall is of a depth equal to the Wall thickness of the honing tool body 100 and is provided with outturned tabs 104 and 106 at the opposite ends thereof and at its radially outer margins which fit within radially outwardly facing grooves 108 and 110 formed in the honing tool body 100. The tabs 104 and 106 are secured to the honing tool body by means of suitable fasteners such as screws 11-2 and -114. Thus, upon axial movement of a honing tool expansion member 116, honing stones 118 may be moved in a radially outward direction without dislodgment of the retainer 96 from its slot.

Honing stones may be inserted within the retainers of each of the embodiments of the present invention by first inserting one end of the stone and thereafter pivoting the opposite end into place. This movement tends to apply a wedging force to the spring tensioning arm of the clip which moves it laterally outwardly to permit the stone to be fully inserted in the slot. Such movement tends to straighten out the arm 54 illustrated in FIGS. l-S, so that the arm 54 is tensioned and frictionally grips the stone. As the arm 54 is straightened out, the pad 60 will ride along the bottom of the recess 62. However, because of the parallel relationship between the pad 60 and the bottom of the groove 62, no unnecessary galling or disfigurement of the bottom of the slot 62 will occur.

It 'has been found that, by the use of a honing tool manufactured in accordance with the present invention, the abrasive action which normally take place between the wall of the slot on the trailing side of the stone (with respect to the direction of normal rotation) and the shell of the stone, is absorbed by the retainer. The retainer will wear on the inner sides thereof and very negligible wear of the side walls of the slot will occur. When the retainer 34 is worn to such an extent that it no longer serves to frictionally retain the honing stones in place adequately, the retainer may be readily removed and replaced. It will be appreciated that the retainer 34 is an inexpensively manufactured stamping and thus may be produced with a minimum of cost. Because of the uniformity of gripping action applied by the arm 54, it has been found that the feed rate of the stones is greatly enhanced, as is the cutting ability of the stones.

While it will be apparent that the preferred embodiments herein illustrated are well calculated to [fulfill the objects above stated, it will be appreciated that the invention is susceptable to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

l. A rotary honing tool including a hollow body mem ber having a radially open slot adapted to receive a honing stone, a honing stone expansion member disposed in said body member for radially outwardly advancing a honing stone disposed in said slot, a honing stone retainer element separate from the honing stone adapted to be received in said slot, said retainer element being removably fitted in said slot and having an elongated wall portion extending along one wall of said slot for :frictionally contacting the honing stone carried in said slot on one side thereof, said wall portion being y'ie'ldable in a direction toward said one slot wall and being operable to maintain said abrasive element out of rubbing engagement with said one slot wall, and means holding said retainer element against radially outward movement upon advancement of the honing stone.

2. A rotary honing tool including a hollow body member having a radially open slot adapted to receive a honing stone, a honing stone expansion member-disposed in said body member for radially advancing a honing stone disposed in said slot, a honing stone retainer element separate from the honing stone adapted to be received in said slot, said retainer element being removably fitted in said slot and having an elongated wall portion covering the major portion of one wall of said slot and operable to frictionally contact said honing stone on one side thereof, said wall portion being yieldable in a direction. toward said one slot wall, and means holding said retainer element against radial movement upon advancement of said honing stone.

3. A rotary honing tool including a hollow body member having a radially open slot provided with opposite side walls adapted to receive a honing stone, a honing stone expansion member disposed in said body member for radial advancement of a honing stone disposed in said slot, a radially open honing stone retainer element removably fitted in said slot and having spaced wall portion adjacent each of said opposite slot walls, one of said wall portions having spring arm means for yieldably biasing said honing stone toward the opposite slot wall, the other of said wall portions being disposed in engagement with said opposite slot wall, and means for holding said retainer element against radial movement upon advancement of the honing stone.

4. A rotary honing tool including a hollow body member having a radially open slot provided with opposite side walls adapted to receive a honing stone, a honing stone expansion member disposed in said body member for radial advancement of a honing stone disposed in said slot, a honing stone retainer element removably fitted in said slot and having an enclosing wall surrounding and engaging said stone on all sides thereof, said Wall having a spring arm portion adjacent to one of said slot walls for frictionally engaging said honing stone, and means for holding said retainer element against substantial radial movement upon radial adjustment of a honing stone in said slot.

5. A rotary honing tool including a hollow body memher having a radially open slot adapted to receive a honing stone, said slot having a pair of opposite side walls and a recess in one of said side walls having a bottom surface substantially parallel to said one side wall, a honing stone expansion member disposed in said body member for radially advancing a honing stone disposed in said slot, a radially open honing stone retainer element removably fitted in said slot and having a spring arm portion adjacent said one side wall provided with a terminal portion engaging said recess bottom wall, said spring arm portion being yieldable in a direction toward said one side wall to bias a honing stone inserted in said slot toward the opposite side wall thereof, and means holding said retainer element against substantial radial movement upon advancement of said honing stone.

6. A rotary honing tool including a hollow body member having a radially open slot adapted to receive a honing stone, a honing stone expansion member disposed in said body member for radially outwardly advancing a honing 3 stone disposed in said slot, a radially open honing stone retainer element separate from the honing stone adapted to be received in said slot, said retainer element being removably fitted in said slot and having an enclosing wall engaging at least a portion of the Walls defining said slot, said enclosing wall having a portion adjacent one wall of said slot adapted to frictionally contact the housing stone carried in said slot on one side thereof, said wall portion being yieldable in a direction toward said one slot wall, and flange means on said wall engageable with said tool body to prevent radially outward movement of said re tainer element upon advancement of said honing stone.

7. A rotary honing tool including a hollow body memher having a radially open slot adapted to receive a honing stone, a honing stone expansion member disposed in said body member for radially outwardly advancing a honing stone disposed in said slot, a radially open honing stone retainer element separate from the honing stone adapted to be received in said slot, said retainer element being removably fitted in said slot and having an elongated wall portion extending along one wall of said slot adapted to frictionally contact the honing stone carried in said slot on one side thereof, said wall portion being yieldable in a direction toward said one slot wall and operable to maintain said abrasive element out of rubbing engagement with said one slot wall, and tab means on said retainer element removably fastened to said honing tool body to prevent radial movement of said retainer element upon advancement of said honing stone.

References Cited in the file of this patent UNITED STATES PATENTS 1,886,584 Prange Nov. 8, 1932 2,201,593 Prange May 21, 1940 3,037,333 Stelrnachowski June 5, 1962 

1. A ROTARY HONING TOOL INCLUDING A HOLLOW BODY MEMBER HAVING A RADIALLY OPEN SLOT ADAPTED TO RECEIVE A HONING STONE, A HONING STONE EXPANSION MEMBER DISPOSED IN SAID BODY MEMBER FOR RADIALLY OUTWARDLY ADVANCING A HONING STONE DISPOSED IN SAID SLOT, A HONING STONE RETAINER ELEMENT SEPARATE FROM THE HONING STONE ADAPTED TO BE RECEIVED IN SAID SLOT, SAID RETAINER ELEMENT BEING REMOVABLY FITTED IN SAID SLOT AND HAVING AN ELONGATED WALL PORTION EXTENDING ALONG ONE WALL OF SAID SLOT FOR FRICTIONALLY CONTACTING THE HONING STONE CARRIED IN SAID SLOT ON ONE SIDE THEREOF, SAID WALL PORTION BEING YIELDABLE IN A DIRECTION TOWARD SAID ONE SLOT WALL AND BEING OPERABLE TO MAINTAIN SAID ABRASIVE ELEMENT OUT OF RUBBING ENGAGEMENT WITH SAID ONE SLOT WALL, AND MEANS HOLDING SAID RETAINER ELEMENT AGAINST RADIALLY OUTWARD MOVEMENT UPON ADVANCEMENT OF THE HONING STONE. 